The failure to understand that today’s financial issues, from Greek debt to the future of the euro, are caused by the mismatch between 20th century health and retirement benefits and new 21st century demographics is finally grabbing global attention. Restructuring how we work and retire in a time of aging populations is not only new – it’s huge.

That is exactly what the World Health Organization is addressing on World Health Day 2012. Healthy lifestyles can transform aging from a time of dependency and disability to one of vitality and productivity. As the WHO shows in its video, “adding life to years” is as essential as it is transformative. If we are going to “save” Greece, the euro, and other currencies and economies around the world, we must begin by re-scripting the social contract for our current century and aligning it to aging populations.

If Twitter offers any indication, the WHO has hit it big this year as the topic of “Ageing and Health” is resonating with audiences around the world. This resonance is occurring within a milieu in which aging populations are beginning to take the stage. In England, Oxford University offered its London Lecture to Dr. Sarah Harper, a gerontologist who delivered a speech entitled, “The 21st Century: The Last Century of Youth?”

And on this side of the Atlantic, Under Secretary of State Robert Hormats and the Council on Foreign Relations made the case that aging populations are integral to future economic growth and deserve a place in our foreign policy framework.

Indeed, as life spans routinely stretch into the 80s and 90s, and as birth rates continue to drop to unprecedented lows, the aging segment of the globe’s population must remain in good health so they can contribute to social and economic life and drive economic competitiveness. With two billion people over 60 by mid-century, our demographic balance has tilted, and the “old” will soon outnumber the “young.” By the year 2050, 33 countries will all have more than 10 million people age 60 or over, including China with 437 million, India at 324 million, the U.S. at 107 Million, Indonesia at 70 million, and Brazil at 58 million. Clearly, the economic and social health of all nations will increasingly depend upon healthy aging.